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Author Question: Of the possible statements that parallel rays are brought to a focus by a 1) concave mirror, 2) ... (Read 224 times) |
Alzheimer's disease affects only about 10% of people older than 65 years of age. Most forms of decreased mental function and dementia are caused by disuse (letting the mind get lazy).
Throughout history, plants containing cardiac steroids have been used as heart drugs and as poisons (e.g., in arrows used in combat), emetics, and diuretics.
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
Oliver Wendell Holmes is credited with introducing the words "anesthesia" and "anesthetic" into the English language in 1846.
Looking at the sun may not only cause headache and distort your vision temporarily, but it can also cause permanent eye damage. Any exposure to sunlight adds to the cumulative effects of ultraviolet (UV) radiation on your eyes. UV exposure has been linked to eye disorders such as macular degeneration, solar retinitis, and corneal dystrophies.